Extra-oral orthodontic appliance and method of making same



Sept. 12, 1967 l. 5 DE WOSKIN EXTRA-ORAL ORTHODONTIC APPLIANCE AND METHOD OF MAKING SAME Filed May 5, 1965 United States Fate'nt C 3,340,613 EXTRA-ORAL ORTHODONTIC APPLIANCE AND METHOD OF MAKING SAME Irvin S. De Woskin, St. Louis, Mo., assignor to Orthoband Company, Inc., St. Louis, Mo., a corporation of Missouri Filed May 5, 1965, Ser. No. 453,248 6 Claims. (Cl. 3214) ABSTRACT OF THE DISCLOSURE An extra-oral orthodontic traction appliance has a U- shaped arch wire and a flexible face bow which are assembled by slipping a heat shrinkable plastic sleeve over the ends of the arch wire and bow and positioning the sleeve centrally of the arch wire and the bow. A sealant is introduced into the sleeve for closing the ends thereof. The sleeve is heated to shrink it on the arch wire and bow. The sleeve, shrunk on the arch wire and bow, holds them in assembled relation and the sealant prevents tartar or other material in the mouth from entering the sleeve.

Extra-oral traction appliances comprising an arch wire and a face bow are known to the art. The face bow and arch wire have conventionally been secured together by silver soldering or welding. However, the heat required in the soldering or welding step may cause the components of the assembly to lose their temper or spring characteristic, which it is important to preserve. Also, solder deposited on the arch wire and bow may be rough and therefore irritating to the mouth or damaging to the teeth.

Accordingly, among the several objects of the invention may be noted the provision of an improved extra-oral orthodontic traction appliance in which there is no loss of temper to the components as a result of-attaching them together; the provision of an extra-oral traction appliance in which the connection between the face bow and arch wire is smooth and nonirritating to the mouth; the provision of an improved extra-oral traction appliance which is free of recesses or holes in which tartar may accumulate; the provision of an improved method for assembling an extra-oral traction appliance in which the arch wire and face how are attached without affecting the temper thereof; and the provision of an improved method for assembling an arch wire and face bow in which the connection between the arch wire and face bow is smooth and nonirritating to the mouth. Other objects and features will be in part apparent and in part pointed out hereinafter.

The invention accordingly comprises the constructions and methods hereinafter described, the scope of the invention being indicated in the following claims.

In the accompanying drawings, in which one of various possible embodiments of the invention is illustrated,

FIG. 1 is a perspective illustrating an extra-oral orthodontic traction appliance of this invention on the teeth of the lower jaw;

FIG. 2 is an enlarged view of the appliance itself;

FIG. 3 is an enlarged section taken on line 33 of FIG. 2; and

FIG. 4 is an enlarged section taken on line 4-4 of FIG. 2.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

Referring to the drawings, an extra-oral orthodontic traction appliance of this invention is shown to comprise a metal arch wire generally designated 1 and a metal face how 3 (made of wire). The arch wire 1 is of U-shape,

having a generally arcuate center portion 5 and two spaced legs 7 diverging from the center portion. As shown in FIG. 2, there is an outwardly projecting cusp 9 at the center of arcuate portion 5. Legs 7 are adapted to be received in buccal tubes such as indicated at 11 held on molar teeth 13 by bands 15. Stop loops 17 on legs 7 limit insertion of the legs into the buccal tubes, thereby confining the outermost ends of the legs in the tubes 11 and preventing injury to the mouth. Arch wire 1 is flexible and has a temper which can be lost by unduly heating the wire.

Face how 3 is of wider U-shape, having a generally arcuate center portion 19 which is shown positioned beneath the arch wire center portion. The face bow center portion is in close fitting relation with the arcuate portion 5 of arch wire 1 and closely conforms to the shape of the arch wire arcuate portion. There is an outwardly projecting cusp 20 at the center of the bow arcuate portions 19. Face how 3 is bowed outwardly adjacent the arcuate center portion 19 as shown at 21, and these bowed portions 21 merge into substantially straight legs generally designated 23. Legs 23 diverge from each other and are hook-shaped at their outermost ends as shown at 25. Hooks 25 provide means for attachment of rubber bands or an elastic strap (not shown) for applying traction in conventional manner. Legs 23 of the face bow are spaced apart a distance greater than the spacing of the legs 7 of the arch wire so that they may be positioned outside of the mouth and adjacent the cheeks of the wearer. The bowed portions 21 of the face bow pass between the lips of the wearer. Face bow 3 is preferably made of a flexible tempered metal so that when it is flexed it will spring back to the shape shown in the drawmgs.

A sleeve 27 holds arch wire 1 and face bow 3 together at their center portions 5 and 19, respectively. Sleeve 27 is made of a heat shrinkable plastic material, such as polyvinyl chloride, and substantially covers the overlapping center portions 5 and 19 of the arch and face how. The sleeve is assembled on wire 1 and face how 3 by slipping the unshrunk sleeve over the legs' of the face bow and arch wire prior to formation of hooks 25 and attachment of stops 17 and then moving the sleeve along face bow and arch wire to the arcuate center portions 5 and 19. Sleeve 27, in its unshrunk condition, is somewhat larger in diameter than the sum of the diameters of wire 1 and how 3 so that it easily slides over them. Once it is in the position illustrated in FIGS. 1 and 2, suflicient heat (which is much lower than that required for soldering or welding) is applied to the sleeve to cause it to shrink and thus tightly clamp the arch wire and face bow together. The heat necessary to shrink polyvinyl chloride is substantially less than that which would effect the temper of the arch wire or face bow and, as a result, shrinking of the sleeve does not impairv the desirable spring quality of either the arch wire or the face bow. The plastic outer surface of sleeve 27 remains soft and smooth even after being heated and therefore is not irritating to the mouth nor damaging to the teeth.

Preferably, the ends of the sleeve 27 are closed by a sealant 29 for preventing accumulation of tartar or other substances in the ends of the tube. As is apparent from FIGS. 2 and 4, the bowed portions 21 of face how 3 begin to diverge from arch wire 1 at the ends of the sleeve, such being greatly exaggerated in FIG. 4 for the purposes of illustration. Unless the resultant spaces or openings were filled by the sealant there would be a dendency for tartar or other substance to accumulate therein. Sealant 29 may be provided by introducing a melted plastic or other sealant material compatible with the tubing 27 into the ends of the tubing and then solidifying the sealant by cooling in the sleeve. For example, when sleeve 27 is polyvinyl chloride, the sealant 29 may be liquid polyvinyl chloride provided by melting some of the tube material. As an alternative, the sealant 29 can be provided by applying clamps to the ends of the sleeve and then applying heat and pressure to the clamped ends of the sleeve for melting the ends of the sleeve until the meltedpolyvinyl chloride fills the space between the arch and face bow and closes the ends of the sleeve.

In order to use the appliance, buccal tubes 11 are fixed to molars 13 and the ends of legs 7 of arch wire 1 are inserted into the buccal tubes, such insertion being limited by the stop loops 17. The bowed portions 21 of the face bow 3 extend out of the mouth of the wearer and the legs 23 of the bow are positioned on the outside of the checks of the wearer. Hooks 25 at the ends of the face bow are then attached to rubber bands connected to a neck band which passes behind the neck or head of the wearer or to an elastic strap to exert the desired traction force on the face bow. The flexible, tempered material of which the face bow is made permits it to flex as necessary. The force applied to the face bow is transmitted through the sleeve 27 to the arch wire. The cusps 9 and 20 prevent relative rotation of the center portions of the wire and the bow.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As various changes could be made in the above constructions and methods without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. An extra-oral orthodontic traction appliance comprising a flexible U-shaped arch wire having a generally arcuate center portion and legs diverging from its center portion, a flexible face bow having a generally arcuate center portion and legs diverging from each other and being spaced apart a distance greater than the spacing of the arch wire legs, the center portion of the arch wire and the center portion of the face bow being in closefitting relation, a sleeve of heat-shrinkable plastic material surrounding the center portions of the arch wire and face bow and shrunk thereon for holding them in assembled relation, and a sealant within said sleeve closing the ends of said sleeve to the entrance of tartar or other material from the mouth.

2. An extra-oral orthodontic traction appliance as set forth in claim 1 wherein the sealant is the same type of plastic material as the sleeve.

3. A method of assembling an extra-oral orthodontic appliance comprising slipping a shrinkable plastic sleeve over the ends of a face bow and an arch wire and moving the sleeve to the center portion of both the face bow and the arch wire, applying heat to shrink the sleeve whereby it tightly grips the face bow and the arch wire, and introducing a sealant into the sleeve for closing the ends of the sleeve.

4. A method of assembling an extra-oral orthodontic appliance as set forth in claim 3 wherein the sealant is the same type of material as the sleeve, and the sealant is introduced into the sleeve in the liquid state and solidified by cooling it in the sleeve.

5. A method of assemblying an extra-oral appliance as set forth in claim 3 wherein the ends of the sleeve are partially melted to seal the ends of the sleeve.

6. A method of assembling an extra-oral orthodontic appliance as set forth in claim 3 wherein the ends of the sleeve are sealed by clamping them to the face bow and arch Wire and applying heat and pressure to the sleeve for partially melting the ends of the sleeve.

References Cited UNITED STATES PATENTS 2,725,823 12/1955 Henschke 29-447 3,036,380 5/1962 Martinek et al 32-l4 OTHER REFERENCES APPCO face bow ad in American Journal of Orthodontics, August 1963, vol. 49, No. 8, page 11.

RICHARD A. GAUDET, Primary Examiner.

J. W. HINEY, Assistant Examiner. 

1. AN EXTRA-ORAL ORTHODONTIC TRACTION APPLIANCE COMPRISING A FLEXIBLE U-SHAPED ARCH WIRE HAVING A GENERALLY ARCUATE CENTER PORTION AND LEGS DIVERGING FROM ITS CENTER PORTION, A FLEXIBLE FACE BOW HAVING A GENERALLY ARCUATE CENTER PORTION AND LEGS DIVERGING FROM EACH OTHER AND BEING SPACED APART A DISTANCE GREATER THAN THE SPACING OF THE ARCH WIRE LEGS, THE CENTER PORTION OF THE ARCH WIRE AND THE CENTER PORTION OF THE FACE BOW BEING IN CLOSEFITTING RELATION, SLEEVE OF HEAT-SHRINKABLE PLASTIC MATERIAL SURROUNDING THE CENTER PORTIONS OF THE ARCH WIRE AND 